Known irrigation emitter units (constituting fluid flow control units of the kind with which the present invention is concerned) comprise, in many cases, an inner member retainably fitted within an outer member, wherein the two members are respectively provided with means which allow for the retainable fitting of the inner member within the outer member and which ensure that, once fitted, the two members are effectively secured to each other, thereby minimising the danger that they inadvertently come apart during use.
It is an object of the present invention to provide a new and improved fluid flow control unit and a process for the manufacture thereof, wherein the constituent members of the flow control unit are effectively retained one within the other, and wherein the mode of retention is itself conducive to the production of an improved unit.